(1) Field of the Invention
The present invention relates to a permanent waving lotion and a process for permanent waving of hair. More particularly, the present invention relates to the second lotion for permanent waving of hair comprising a hydrogen peroxide solution having certain properties such that consecutive decline of the modulus of the hair due to repeated permanent waving processes can be prevented, and a process for permanent waving of hair using said second lotion.
(2) Description of the Prior Art
As the means to impart a lasting curl to hair, which is so-called "cold waving" the means of achieving permanent waving without any need for heat using an aqueous alkaline solution, is conventionally adopted instead of the method which depends on heating of the hair to a high temperature.
The cold waving method is usually performed in the manner as described in the following:
First of all, strands of hair is wound around rods, a reducing agent consisting of a mixture of ammonium thioglycolate, ammonium bicarbonate, ammonia water and the like is applied to the strands of hair as the first lotion, and the head wrapped up in a cap is allowed to stand for about 5 to 20 minutes. By aforesaid treatments, cleavage of the disulfide bond (--S--S--) in keratin fiber of the hair is ruptured, and the hair is consequently plasticized and a deformation of the strands of hair is given. And then the reducing process is terminated by either once removing the first lotion (the reducing agent) or neutralizing the reducing agent by an acidic solution. At this stage many disulfide groups in keratin fiber of the hair have changed into mercapto groups (--SH). Next, the deformation given to the strands of hair is fixed by means of applying to them sodium bromate solution or hydrogen peroxide solution as the second lotion (the oxidizing agent) and then allowing them to stand for about 15 minutes to have the SH groups to be oxidized and converted back into disulfide groups. Finally, the second lotion is rinsed off and the hair is dried to complete the cold waving.
People who have their hair permed visit beauty shops ordinarily every two or three months in their efforts to continually impart a curl to their hairs.
However, according to the conventional process, it has been inevitable for the processed hair to become law stiffness, coarse and lusterless, so-called "damaged hair", inasmuch as modulus of the hair is reduced and its surface smoothness and gloss decreases due to the reducing step and oxidizing step which is inevitably undergoes repeatedly.
In the past, there have been proposed methods to overcome development of damages to the hair. Such methods include use of cysteine or the like as a weaker reducing agent which is obtained by modifying the composition of the conventional first lotion, changing of the pH value or concentration of the first lotion, and admixing of additives to the first lotion or second lotion. Neither one of the said methods, however, has proved effective to prevent consecutive decline in the modulus of the hair by repeated permanent wavings.